''Sequoia affinis'' is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Sequoia'' in the cypress family

Cupressaceae Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdio ...

. The name Sequoia sometimes refers to the subfamily Sequoioideae, which includes the still-living '' Sequoia sempervirens'' along with '' Sequoiadendron'' (giant sequoia) and ''

Metasequoia ''Metasequoia'', or dawn redwoods, is a genus of fast-growing deciduous trees, one of three species of pinophyta, conifers known as redwoods. The living species ''Metasequoia glyptostroboides'' is native to Lichuan, Hubei, Lichuan county in Hube ...

'' (dawn redwood). On its own, the term redwood usually refers to the coast redwood ('' Sequoia sempervirens''), and not to species in the other genera. There are many ''Sequoia'' fossils found at the

Florissant fossil beds The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and ...

Florissant, Colorado Florissant is an unincorporated town, a post office, and a census-designated place (CDP) located in and governed by Teller County, Colorado, United States. The CDP is a part of the Colorado Springs, CO Metropolitan Statistical Area. The Floriss ...

, including ''Sequoia affinis''. A trio of ''Sequoia affinis'' fossilized stumps—believed to be three basal shoot clones of one original parent tree—has been reconstructed at this site. Many branches of fossil ''Sequoia'' from Florissant have foliage with spreading leaves, which is also common in the modern ''Sequoia''. The leaves in the fossil species, however, are usually thinner and more delicate. An example of the leaves of ''Sequoia affinis'' has been featured on a postcard in a series on "Tertiary Fossil Plants," issued by the British Museum of Natural History in the early 1920s. It has also been suggested that ''Sequoia affinis'' may be ancestral to both ''Sequoia sempervirens'' and ''Sequoiadendron giganteum'' (Sierra redwood). Typically the female cones of ''Sequoia affinis'' are only 50-70% of the length of modern redwood cones. This information, paired with other differences in the wood, foliage, and pollen, show the distinction between ''Sequoia affinis'' and ''Sequoia sempervirens''. Fossilized ''Sequoia affinis'' pollen has been discovered in lake-sediment shale at the site in Florissant, Colorado.

References

affinis Prehistoric trees {{paleo-conifer-stub